SACRAMENTO (AP) — California lawmakers may have given their OK to what could be the nation’s first high-speed rail line, but the project is still a long way from leaving the station.

The project has prominent supporters such as President Barack Obama and Gov. Jerry Brown, but supporters must still overcome a number of challenges, including environmental concerns, clashes with local leaders over land use, a $68 billion overall price tag with no funding guarantees and an increasingly disenchanted public.

Supporters applauded Friday when the state Legislature narrowly approved $4.5 billion in state funding for rail improvements and to begin construction on the initial segment of high-speed track in the agricultural Central Valley. The move enabled the state to tap $3.2 billion in federal bond money.

Critics, however, are redoubling their efforts to derail the project that could eventually link Los Angeles and San Francisco with trains traveling up to 220 mph.

Among those gearing up for a fight are the farmers whose land lies in the path of the massive infrastructure project.

The Madera and Merced county farm bureaus, along with other parties, have filed a lawsuit to halt the project on grounds that the state has not done enough environmental vetting. The plaintiffs say the train would render 1,500 acres of fertile land unfarmable and disrupt 500 agricultural businesses.

“We are going to protect our property,” said Frank Oliveira, a farmer and leader of the Central Valley group Citizens For California High-Speed Rail school. Accountability. “Somebody is coming into our area, and they are going to seize our property and say we don’t have a choice in the matter.”

Brown has made the project a touchstone of his administration. He had initially attempted to prevent courts from using the state’s complex environmental law to stop construction but backed down from that proposal under pressure as he sought to win lawmakers’ approval.

U.S. Transportation Secretary Ray LaHood on Monday praised Democratic lawmakers for approving the project, despite intense pressure from critics, saying it reinforces California’s position as a leader in high-speed rail.

“The president’s vision is to get America to have highspeed rail. There’s no better place to do it than in California,” he told reporters at San Francisco International Airport.